Remnants of a huge flood on Mars have been discovered, according to the European Space Agency, which has captured phenomenal high-definition photos of one of the largest ‘outflow channels’ on the red planet.

The ESA says a combination of volcanism, tectonics, and surface collapse and subsidence led to a “massive groundwater release” from the Echus Chasma region on Mars around 3.6 to 3.4 billion years ago.

Meanwhile, the debris surrounding another smaller crater close by is undisturbed, suggesting that this impact was made after the flooding. A splash-like pattern of the debris ejected from the crater provides further evidence that this impact occurred while water covered the surface.